The disclosures of the following applications are herein incorporated by reference:
Japanese Patent Application No. 10-151278 filed Jun. 1, 1998
Japanese Patent Application No. 10-277166 filed Sep. 30, 1998
Japanese Patent Application No. 11-145473 filed May 25, 1999
Japanese Patent Application No. 2000-186367 filed Jun. 21, 2000
PCT Application No. PCT/JP99/02887 filed May 31, 1999
1. Field of the Invention
The present invention relates to an interpolation processing apparatus that implements interpolation processing for obtaining an interpolation quantity which is equivalent to color information corresponding to a first color component for each vacancy in an image generated by an image-capturing sensor having a plurality of lattice points and a plurality of vacancies in a two-dimensional array with the lattice points each outputting color information corresponding to the first color component and the vacancies each outputting color information corresponding to a second color component or a third color component without outputting color information corresponding to the first color component, and it also relates to a recording medium for recording an interpolation processing program utilized to execute the interpolation processing on a computer.
2. Description of the Related Art
Some electronic still cameras utilize a single image-capturing sensor to generate image signals of a color image. Such an image-capturing sensor may be constituted by arranging color filters in three colors, i.e., R, G and B (red, green and blue) in a Bayer array, as illustrated in FIG. 22A. With regard to the green color (G), the image-capturing sensor can be regarded as being composed of lattice points each constituted of a pixel that outputs green color and vacancies each constituted of a pixel which does not output green color, as shown in FIG. 22B.
In this type of electronic still camera, it is necessary to implement interpolation processing in order to obtain green color information at each vacancy. For this application, an interpolation processing method in which an interpolation quantity is calculated by judging the direction along which a vacancy undergoing the interpolation processing (hereafter referred to as an interpolation target vacancy) manifests a high degree of spatial similarity and using the color information at lattice points adjacent to the interpolation target vacancy along the direction has been proposed in the prior art.
U.S. Pat. Nos. 5,629,734 and 5,652,621 each disclose a technology for calculating similarity degrees along a plurality of directions to be used when judging the direction manifesting a pronounced similarity.
For instance, if color information is provided around the interpolation target vacancy expressed as xe2x80x9cA1, G2, A3, G4, A5xe2x80x9d (with A1, A3 and A5 each representing color information corresponding to the same-color component as that at the interpolation target vacancy and G2 and G4 each representing color information at a lattice point), a similarity degree C of the interpolation target vacancy along the direction in which the lattice point outputting G2 and the lattice point outputting G4 is set is calculated through the following expression C-1 in the technology disclosed in U.S. Pat. No. 5,629,734, whereas the similarity degree C is calculated through expression C-2 in the technology disclosed in U.S. Pat. No. 5,652,621.
C=|xe2x88x92A1+2A3xe2x88x92A5|+|G2xe2x88x92G4|xe2x80x83xe2x80x83expression C-1
C=|xe2x88x92A1+2A3xe2x88x92A5|+|G2xe2x88x92G4|+|xe2x88x92G2+2(A3+bias)xe2x88x92G4|xe2x80x83xe2x80x83expression C-2
with xe2x80x9cbiasxe2x80x9d in expression C-2 representing a value satisfying
bias=(biasxe2x80x2+A1xe2x88x92G1)/2xe2x80x83xe2x80x83expression C-3,
in which xe2x80x9cbiasxe2x80x2xe2x80x9d represents the bias used to calculate the similarity degree of A1 and G1 indicates the interpolation quantity ascertained through the interpolation processing implemented on A1.
In the technology disclosed in U.S. Pat. No. 5,629,734, the results obtained by comparing color information corresponding to a single color component at every other pixel (hereafter referred to as same-color similarity components: correspond to |xe2x88x92A1+2A3xe2x88x92A5| and |G2xe2x88x92G4| in expression C-1) are added and the sum is used as the similarity degree of the interpolation target vacancy. Thus, since similarity degree in an image which changes in smaller increments than the intervals (equivalent to twice the intervals between individual pixels) over which the same-color information is provided (an image with a high spatial frequency) cannot be accurately calculated through the technology disclosed in U.S. Pat. No. 5,629,734, the judgment with regard to the direction manifesting a pronounced similarity cannot be made with a high degree of accuracy, thereby presenting a high likelihood of color artifacs (or false color).
Through the technology disclosed in U.S. Pat. No. 5,652,621, on the other hand, in which the similarity degree is calculated through expression C-2 which incorporates the results of a comparison of color information at adjacent pixels (hereafter referred to as a xe2x80x9cdifferent-color similarity componentxe2x80x9d: correspond to |xe2x88x92G2+2(A3+bias)xe2x88x92G4| in expression C-2) with the same-color similarity components (correspond to |xe2x88x92A1+2A3xe2x88x92A5| and |G2xe2x88x92G4| in expression C-2), the occurrence of color artifacts can be reduced in an image with a high spatial frequency.
However, since the results of a comparison of color information corresponding to only two colors set on a single straight line (color information corresponding to the same-color component as that at the interpolation target vacancy and color information at a lattice point) are used as a different-color similarity component in the technology disclosed in U.S. Pat. No. 5,652,621, the similarity degree cannot be calculated with accuracy in an area where the color tone changes (an image in which the ratio of the color information corresponding to the three colors changes) as in a border area in a natural image and the influence of the different-color similarity components manifests to a greater degree than the influence of the same-color similarity components even when the same-color similarity components are calculated accurately, which presents difficulty in judging the direction along which a pronounced similarity manifests with accuracy, resulting in a high likelihood of occurrence of color artifacts.
In other words, when interpolating an image which includes an image area with a high spatial frequency and an image area where the color tone changes through either of the technologies disclosed in the U.S. patent specifications mentioned above, the similarity degrees in the two image areas in the image cannot be calculated accurately, resulting in the color artifacts occurring in either image area becoming conspicuous to disrupt the harmony of the entire image.
In addition, since the different-color similarity component is calculated by using G1 (interpolation quantity at A1) and biasxe2x80x2 (bias at A1) in the technology disclosed in U.S. Pat. No. 5,652,621, once a similarity component is calculated erroneously, the error affects similarity components to be calculated subsequently, which presents a concern that the range over which color artifacts occur may expand.
In other words, in the worst scenario, by implementing interpolation processing through the technology disclosed in U.S. Pat. No. 5,652,621, the quality of the image may even become worse.
Accordingly, an object of the present invention is to provide an interpolation processing apparatus capable of calculating an interpolation quantity with a high degree of accuracy by accurately judging the direction along which the interpolation target vacancy manifests a pronounced similarity. Another object of the present invention is to provide a recording medium in which an interpolation processing program for calculating an interpolation quantity with a high degree of accuracy by accurately judging the direction along which the interpolation target vacancy manifests a pronounced similarity is recorded.
In order to attain the above object, an interpolation processing apparatus that performs interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy, comprises: a similarity degree calculation unit that calculates two types of similarity components along each of a plurality of directions, which are a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component and color information corresponding to the second color componentxe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component and color information corresponding to the third color componentxe2x80x9d, for an interpolation target vacancy to undergo the interpolation processing based upon color information corresponding to the first through third color components output from the interpolation target vacancy and lattice points and vacancies near the interpolation target vacancy, and then calculates similarity degrees based upon the two types of similarity components; a similarity judgment unit that makes a judgment with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation unit; and an interpolation quantity calculation unit that calculates the interpolation quantity for the interpolation target vacancy in conformance to results of the judgment made by the similarity judgment unit.
In this interpolation processing apparatus, it is preferred that, the similarity degree calculation unit calculates at least three types of similarity components along each of the plurality of directions, including at least one type of similarity component among a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity component obtained by using color information corresponding to the second color component alonexe2x80x9d and xe2x80x9ca xe2x80x9csimilarity component obtained by using color information corresponding to the third color component alonexe2x80x9d, and calculates the similarity degrees based upon the at least three types of similarity components.
Also, it is preferred that the similarity degree calculation unit calculates the similarity degrees for the interpolation target vacancy along the plurality of directions by combining a plurality of types of similarity components obtained along each of the plurality of directions through weighted addition of similarity components performed along each direction.
Also, it is preferred that the similarity degree calculation unit calculates the similarity degrees for the interpolation target vacancy by using a similarity component calculated on a vacancy located near the interpolation target vacancy.
Also, it is preferred that the similarity judgment unit makes a decision as to whether or not a difference between similarity degrees along individual directions exceeds a specific threshold value and judges that roughly equal similarity degrees manifest along the directions if the difference does not exceed the threshold value.
Also, it is preferred that when the similarity judgment unit judges that one of the plurality of directions manifests pronounced similarity, the interpolation quantity calculation unit calculates an average of values indicated by color information from two lattice points set along the direction manifesting pronounced similarity as the interpolation quantity, whereas when the similarity judgment unit judges that similarity degrees manifested along the plurality of directions are close to each other, the interpolation quantity calculation unit ascertains an interpolation quantity through another method without calculating an average of values indicated by color information from two lattice points set along one of the plurality of directions.
An interpolation processing apparatus that performs interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy, comprises: a similarity degree calculation unit that calculates at least two types of similarity components along each of a plurality of directions including (a) a xe2x80x9csimilarity component obtained by using color information at a vacancy that outputs color information corresponding to a color component different from a color component of the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and (b) at least one type of similarity component among a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity component obtained by using color information corresponding to the second color component alonexe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the third color component alonexe2x80x9d, for an interpolation target vacancy to undergo the interpolation processing, based upon color information corresponding to the first through third color components output from the interpolation target vacancy and lattice points and vacancies near the interpolation target vacancy, and then calculates similarity degrees based upon the at least two types of similarity components; a similarity judgment unit that makes a judgment with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation unit; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target vacancy in conformance to results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy, comprises: a similarity degree calculation unit that calculates similarity degrees along a plurality of directions for an interpolation target vacancy to undergo the interpolation processing; a similarity judgment unit that makes a judgment with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation unit; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target vacancy in conformance to results of the judgment made by the similarity judgment unit. And the similarity degree calculation unit calculates at least two types of similarity components along each of the plurality of directions including (a) a xe2x80x9csimilarity component obtained by using color information output from the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and (b) at least one type of similarity component among a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity component obtained by using color information corresponding to the second color component alonexe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the third color component alonexe2x80x9d, based upon color information corresponding to the first through third color components output from the interpolation target vacancy and lattice points and vacancies near the interpolation target vacancy, and then calculates similarity degrees based upon the at least two types of similarity components; and the xe2x80x9csimilarity component obtained by using color information from the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d is calculated through xe2x80x9ca1|G1xe2x88x92A2|+a2|G3xe2x88x92A2xe2x80x9d in which G1 and G3 represent color information at two lattice points set on a single straight line with the interpolation target vacancy located in between, A2 represents the color information at the interpolation target vacancy and a1 and a2 each represent a constant with at least either a1 or a2 not equal to 0.
An interpolation processing apparatus that performs interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy, comprises: a similarity degree calculation unit that calculates at least two types of similarity degrees among a xe2x80x9csimilarity degree obtained by using color information corresponding to the first color component and color information corresponding to the second color componentxe2x80x9d, a xe2x80x9csimilarity degree obtained by using color information corresponding to the first color component and color information corresponding to the third color componentxe2x80x9d, a xe2x80x9csimilarity degree obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity degree obtained by using color information corresponding to the second color component alonexe2x80x9d and a xe2x80x9csimilarity degree obtained by using color information corresponding to the third color component alonexe2x80x9d as similarity degrees along a plurality of directions manifesting at an interpolation target vacancy, based upon color information corresponding to the first through third color components output from the interpolation to undergo the interpolation processing and lattice points and vacancies near the interpolation target vacancy; a similarity judgment unit that makes a judgment with respect to a direction manifesting pronounced similarity relative to the interpolation target vacancy by comparing, along each direction, similarity degrees of a single type among a plurality of types of similarity degrees along the plurality of directions calculated for the interpolation target vacancy by the similarity degree calculation unit, determining a direction manifesting pronounced similarity for each type of similarity degree and ascertaining a direction being in a majority of directions manifesting pronounced similarity; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target vacancy in conformance to results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy, comprises: a similarity degree calculation unit that calculates at least one type of similarity component among two types of similarity components, which are a xe2x80x9csimilarity component obtained by using color information from an interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d as similarity components along a plurality of directions for the interpolation target vacancy based upon color information output from the interpolation target vacancy undergoing the interpolation processing and lattice points and vacancies near the interpolation target vacancy, and calculates similarity degrees along a plurality of directions for the interpolation target vacancy based upon the at least one type of similarity component; a similarity judgment unit that makes a judgment with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation unit; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target vacancy in conformance to results of the judgment made by the similarity judgment unit. And the similarity degree calculation unit extracts characteristics of an image over an area surrounding the interpolation target vacancy and calculates one type of similarity component selected in conformance to the characteristics among the two types of similarity components as the similarity degree, or calculates the similarity degree by calculating the two types of similarity components and performing weighted addition of the calculated two types of similarity components while adjusting a weighting ratio in correspondence to the characteristics.
In this interpolation processing apparatus, it is preferred that the similarity degree calculation unit calculates the xe2x80x9csimilarity degrees obtained by using color information from the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d when the characteristics of the image in the area around the interpolation target vacancy indicate that sets of color information from a plurality of lattice points set along a first direction among two directions intersecting at a right angle at the interpolation target vacancy are highly similar, that sets of color information from a plurality of lattice points set along a second direction among the two directions are highly similar and that the color information from lattice points set along the first direction is greatly different from the color information from lattice points set along the second direction.
An interpolation processing apparatus that performs interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy, comprises: a similarity degree calculation unit that calculates at least one type of similarity component among two types of similarity components, which are a xe2x80x9csimilarity component obtained by using color information from an interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d as similarity components along a plurality of directions for the interpolation target vacancy based upon color information output from the interpolation target vacancy undergoing the interpolation processing and lattice points and vacancies near the interpolation target vacancy, and calculates similarity degrees along a plurality of directions for the interpolation target vacancy based upon the at least one type of similarity component; a similarity judgment unit that makes a judgment with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation unit; an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target vacancy in conformance to results of the judgment made by the similarity judgment unit; and an interface unit that receives a first instruction indicating which of the two types of similarity components is to be calculated or a second instruction indicating a weighting rate to be used when performing weighted addition of the two types of similarity components. And the similarity degree calculation unit calculates one type of similarity component as indicated by the first instruction as the similarity degree when the first instruction has been received at the interface unit, and calculates the similarity degrees through weighted addition of the two types of similarity components implemented in response to the second instruction when the second instruction has been received at the interface unit.
A recording medium has an interpolation processing program recorded therein for enabling a computer to execute interpolation processing on an image generated by an image-capturing sensor constituted by two dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy. The interpolation processing program comprises: a similarity degree calculation step in which two types of similarity components along each of a plurality of directions, which are a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component and color information corresponding to the second color componentxe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component and color information corresponding to the third color componentxe2x80x9d, are calculated for an interpolation target vacancy to undergo the interpolation processing based upon color information corresponding to the first through third color components output from the interpolation target vacancy and lattice points and vacancies near the interpolation target vacancy, and then similarity degrees are calculated based upon the two types of similarity components; a similarity judgment step in which a judgment is made with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated in the similarity degree calculation step; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target vacancy is calculated in conformance to results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program recorded therein for enabling a computer to execute interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy. The interpolation processing program comprises: a similarity degree calculation step in which at least two types of similarity components along each of a plurality of directions including (a) a xe2x80x9csimilarity component obtained by using color information at a vacancy that outputs color information corresponding to a color component different from a color component of the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and (b) at least one type of similarity component among a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity component obtained by using color information corresponding to the second color component alonexe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the third color component alonexe2x80x9d, are calculated for an interpolation target vacancy to undergo the interpolation processing, based upon color information corresponding to the first through third color components output from the interpolation target vacancy and lattice points and vacancies near the interpolation target vacancy, and then similarity degrees are calculated based upon the at least two types of similarity components; a similarity judgment step in which a judgment is made with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation step; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target vacancy is calculated in conformance to results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program recorded therein for enabling a computer to execute interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy. The interpolation processing program comprises: a similarity degree calculation step in which similarity degrees along a plurality of directions are calculated for a interpolation target vacancy to undergo the interpolation processing; a similarity judgment step in which a judgment is made with respect to a direction manifesting pronounced similarity for the interpolation target vacancy based upon the similarity degrees along the plurality of directions calculated by the similarity degree calculation step; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target vacancy is calculated in conformance to results of the judgment made in the similarity judgment step. And in the similarity degree calculation step at least two types of similarity components are calculated along the plurality of directions including (a) a xe2x80x9csimilarity component obtained by using color information output from the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d (b) at least one type of similarity component among a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity component obtained by using color information corresponding to the second color component alonexe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the third color component a onexe2x80x9d, based upon color information corresponding to the first through third color components output from the interpolation target vacancy and lattice points and vacancies near the interpolation target vacancy, and then the similarity degrees are calculated based upon the at least two types of similarity components; and the xe2x80x9csimilarity component obtained by using color information from the interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d calculated through xe2x80x9ca1|G1xe2x88x92A2|+a2|G3xe2x88x92A2|xe2x80x9d in which G1 and G3 represent color information at two lattice points set on a single straight line with the interpolation target vacancy located in between, A2 represents color information at the interpolation target vacancy and a1 and a2 each represent a constant with at least either a1 or a2 not equal to 0.
A recording medium has an interpolation processing program recorded therein for enabling a computer to execute interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy. The interpolation processing program comprises: a similarity degree calculation step in which at least two types of similarity degrees among a xe2x80x9csimilarity degree obtained by using color information corresponding to the first color component and color information corresponding to the second color componentxe2x80x9d, a xe2x80x9csimilarity degree obtained by using color information corresponding to the first color component and color information corresponding to the third color componentxe2x80x9d, a xe2x80x9csimilarity degree obtained by using color information corresponding to the first color component alonexe2x80x9d, a xe2x80x9csimilarity degree obtained by using color information corresponding to the second color component alonexe2x80x9d and a xe2x80x9csimilarity degree obtained by using color information corresponding to the third color component alonexe2x80x9d are calculated as similarity degrees along a plurality of directions manifesting at an interpolation target vacancy based upon color information corresponding to the first through third color components output from the interpolation target vacancy to undergo the interpolation processing and lattice points and vacancies near the interpolation target vacancy; a similarity judgment step in which a judgment is made with respect to a direction manifesting pronounced similarity relative to the interpolation target vacancy by comparing, along each direction, similarity degrees of a single type among a plurality of types of similarity degrees calculated along the plurality of directions for the interpolation target vacancy in the similarity degree calculation step, determining a direction manifesting pronounced similarity for each type of similarity degree and ascertaining a direction being in a majority of directions manifesting pronounced similarity; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target vacancy is calculated in conformance to results of judgment made in the similarity judgment step.
A recording medium has an interpolation processing program recorded therein for enabling a computer to execute interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy. The interpolation processing program comprises: a similarity degree calculation step in which at least one type of similarity components among two types of similarity components, which are a xe2x80x9csimilarity component obtained by using color information from an interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d is calculated as similarity component along a plurality of directions for the interpolation target vacancy based upon color information output from the interpolation target vacancy undergoing the interpolation processing and lattice points and vacancies set near the interpolation target vacancy, and similarity degrees along a plurality of directions for the interpolation target vacancy are calculated based upon the at least one type of similarity components; a similarity judgment step in which a judgment is made with respect to a direction manifesting pronounced similarity for the interpolation target vacancy is judged based upon the similarity degrees along the plurality of directions calculated in the similarity degree calculation step; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target vacancy is calculated in conformance to results of the judgment made in the similarity judgment step. In the similarity degree calculation step, characteristics of an image over an area surrounding the interpolation target vacancy is extracted, and one type of similarity component selected in conformance to the characteristics among the two types of similarity components is calculated as the similarity degrees, or the similarity degrees are calculated by calculating two types of similarity degrees and performing weighted addition of the two types of similarity components while adjusting a weighting ratio in correspondence to the characteristics.
A recording medium has an interpolation processing program recorded therein for enabling a computer to execute interpolation processing on an image generated by an image-capturing sensor constituted by two-dimensionally arraying a plurality of lattice points each of which outputs color information corresponding to a first color component and a plurality of vacancies each of which outputs color information corresponding to a second color component or a third color component instead of outputting color information corresponding to the first color component, to determine an interpolation quantity equivalent to color information corresponding to the first color component for a vacancy. The interpolation processing program comprises: a similarity degree calculation step in which at least one type of similarity components among two types of similarity components, which are a xe2x80x9csimilarity component obtained by using color information from an interpolation target vacancy and color information corresponding to the first color componentxe2x80x9d and a xe2x80x9csimilarity component obtained by using color information corresponding to the first color component alonexe2x80x9d is calculated as similarity component along a plurality of directions for the interpolation target vacancy based upon color information output from the interpolation target vacancy undergoing the interpolation processing and lattice points and vacancies set near the interpolation target vacancy, and similarity degrees along a plurality of directions for the interpolation target vacancy are calculated based upon the at least one type of similarity components; a similarity judgment step in which a judgment is made with respect to a direction manifesting pronounced similarity for the interpolation target vacancy is judged based upon the similarity degrees along the plurality of directions calculated in the similarity degree calculation step; an interpolation quantity calculation step in which an interpolation quantity for the interpolation target vacancy is calculated in conformance to results of the judgment made in the similarity judgment step; and an interface step in which a first instruction indicating which of the two types of similarity components is to be calculated is received or a second instruction indicating a weighting rate to be used when performing weighted addition of the two types of similarity components is received. And in the similarity degree calculation step, one type of similarity component is calculated as indicated by the first instruction as the similarity degrees when the first instruction has been received in the interface step, and the similarity degrees are calculated through weighted addition of the two types of similarity components implemented in response to the second instruction when the second instruction has been received in the interface step.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d calculated with a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color is information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
In this interpolation processing apparatus, it is preferred that the similarity degree calculation unit calculates a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of one or more color components and calculates the each of similarity degrees by using the same-color similarity component together with the different-color similarity component.
Also, it is preferred that the similarity degree calculation unit calculates the similarity degrees manifesting at the interpolation target pixel by incorporating similarity components calculated for pixels located around the interpolation target pixel as well as the similarity components calculated for the interpolation target pixel.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along at least two directions relative to an interpolation target pixel to undergo interpolation processing by using color information corresponding to three different color components and a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color information to a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs is interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along at least two directions relative to an interpolation target pixel to undergo interpolation processing by using color information corresponding to three different components and a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to two different color componentsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of three color components, by calculating a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d and by utilizing the similarity components in combination with each other; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d for each of three color components, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of two or more color components and by utilizing the similarity components in combination with each other; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to two different color componentsxe2x80x9d and a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color component calculated with a similarity degree element constituted of color information from two pixelsxe2x80x9d; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color component calculated with a similarity degree element constituted of color information from two pixelsxe2x80x9d for each of two or more color components, and by performing weighted addition of the same-color similarity components; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to a color component different from the color component of the interpolation target pixel and the first color component and color information corresponding to the first color componentxe2x80x9d; a similarity judgment unit that makes a judgment on degrees of similarity along the individual direction, based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, for each of two types of similarity degrees, which are a xe2x80x9csimilarity degree containing a different-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d and a xe2x80x9csimilarity degree containing a same-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d, by switching to either type of similarity degrees or switching weighting ratios to be used in weighted addition of the similarity degrees in correspondence to characteristics of an image over an area surrounding the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component for a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two dimensional array and output color information corresponding to different color components which are firstxcx9cthird color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d calculated with a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d calculated with a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
In this interpolation processing apparatus, it is preferred that the similarity degree calculation unit calculates a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of one or more color components and calculates the each of similarity degrees by using the same-color similarity component together with the different-color similarity component.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along at least two directions relative to an interpolation target pixel to undergo interpolation processing by using color information corresponding to three or more different color components and a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual direction based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises a similarity degree calculation unit that calculates each of similarity degrees along at least two directions relative to an interpolation target pixel to undergo interpolation processing by using color information corresponding to three or more different components and a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to two different color componentsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises; a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of three or more color components, by calculating a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d and by utilizing the similarity components in combination with each other; a similarity judgment unit that makes a judgment on degrees of similarity along the individual direction based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d for each of three or more color components, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of two or more color components and by utilizing the similarity color components in combination with each other; a similarity judgment unit that makes a judgment on degrees of similarity along the individual direction based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to two different color componentsxe2x80x9d and a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color component calculated with a similarity degree element constituted of color information from two pixelsxe2x80x9d; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color component calculated with a similarity degree element constituted of color information from two pixelsxe2x80x9d for each of two or more color components, and by performing weighted addition of the same-color similarity component; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to a color component different from the color component of the interpolation target pixel and the first color component and color information corresponding to the first color componentxe2x80x9d; a similarity judgment unit that makes a judgment on degrees of similarity along the individual direction based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
An interpolation processing apparatus that performs interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component, comprises: a similarity degree calculation unit that calculates each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, for each of two types of similarity degrees, which are a xe2x80x9cdifferent-color similarity degree containing a different-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d and a xe2x80x9csame-color similarity degree containing a same-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d, by switching to either type of similarity degrees or switching weighting ratios to be used in weighted addition of the similarity degrees in correspondence to characteristics of an image over a local area containing the interpolation target pixel; a similarity judgment unit that makes a judgment on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation unit that calculates an interpolation quantity for the interpolation target pixel based upon results of the judgment made by the similarity judgment unit.
In this interpolation processing apparatus, it is preferred that the similarity degree calculation unit calculates the similarity degrees manifesting at the interpolation target pixel by incorporating similarity components calculated for pixels located around the interpolation target pixel as well as the similarity components calculated for the interpolation target pixel.
Also, it is preferred that the similarity degree calculation unit uses information related to color as characteristics of the image in the local area containing the interpolation target pixel. In this case, it is preferred that when the plurality of pixels that output color information corresponding to the firstxcx9cnth (nxe2x89xa72) color components different from each other output color information corresponding to the firstxcx9cthe third color components different from each other and the first color component achieves a higher spatial frequency compared to the second color component and the third color component, the similarity degree calculation unit calculates, as the different-color similarity degrees, similarity degrees each containing at least one of (1) a different-color similarity component obtained by using color information corresponding to the first color component and color information corresponding to the second color information, and (2) a different-color similarity component obtained by using color information corresponding to the first color component and color information corresponding to the third color component, and calculates, as the same-color similarity degrees, similarity degrees each containing at least one of (1) a same-color similarity component obtained by using color information corresponding to the first color component alone, (2) a same-color similarity component obtained by using color information corresponding to the second color component alone, and (3) the same-color similarity component obtained by using color information corresponding to the third color component alone. Or, it is preferred that the similarity degree calculation unit makes a decision as to whether the image over the local area is an achromatic image or a chromatic image in reference to the information related to color, and if the image in the local area is achromatic, the similarity degree calculation unit selects the different-color similarity degree as similarity degrees along a plurality of directions relative to the interpolation target pixel or sets a weighting coefficient for the different-color similarity degree to be used in weighted addition of the different-color similarity degree and the same-color similarity degree higher than a weighting coefficient for the same-color similarity degree, whereas if the image in the local area is chromatic, the similarity degree calculation unit selects the same-color similarity degree as similarity degrees along the plurality of directions relative to the interpolation target pixel or sets the weighting coefficient for the same-color similarity degree to be used in weighted addition of the different-color similarity degree and the same-color similarity degree higher than the weighting coefficient for the different-color similarity degree. Or, it is preferred that the similarity degree calculation unit uses the different-color similarity degree as the information related to color, and furthermore it is preferred that wherein if the different-color similarity degrees indicate pronounced similarity along at least, one direction, the similarity degree calculation unit determines the image over the local area to be an achromatic image, and the similarity degree calculation unit determines the image in the local area to be a chromatic image otherwise. Or, it is preferred that the similarity degree calculation unit uses, as the similarity degrees along a plurality of directions relative to the interpolation target pixel, similarity degrees along a plurality of directions calculated for pixel around the interpolation target pixel as well as for the interpolation target pixel.
Also, it is preferred that the similarity degree calculation unit calculates the different-color similarity degree by using color information from pixels present over shorter intervals compared to pixels that output the color information used to calculate the same-color similarity degree.
Also, it is preferred that the similarity degree calculation unit determines that essentially equal degrees of similarity manifest along a plurality of directions if differences of similarity degrees along the plurality of directions are smaller than a specific threshold value.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d calculated with a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along at least two directions relative to an interpolation target pixel to undergo interpolation processing is calculated by using color information corresponding to three or more different color components and a xe2x80x9csimilarity degree element constituted of color information from three or fewer pixelsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along at least two directions relative to an interpolation target pixel to undergo interpolation processing is calculated by using color information corresponding to three or more different components and a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to two different color componentsxe2x80x9d, based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel; similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of three or more color components, by calculating a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d and by utilizing the similarity components in combination with each other; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d for each of three or more color components, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d for each of two or more color components and by utilizing the similarity color components in combination with each other; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to two different color componentsxe2x80x9d and a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color component calculated with a similarity degree element constituted of color information from two pixelsxe2x80x9d; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon result of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by calculating a xe2x80x9csame-color similarity component obtained by using color information corresponding to a single color component calculated with is a similarity degree element constituted of color information from two pixelsxe2x80x9d for each of two or more color components, and by performing weighted addition of the same-color similarity components; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa73) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, by using a xe2x80x9cdifferent-color similarity component obtained by using color information corresponding to a color component different from the color component of the interpolation target pixel and the first color component and color information corresponding to the first color componentxe2x80x9d; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.
A recording medium has an interpolation processing program for performing interpolation to obtain color information corresponding to a first color component of a pixel, in which the first color component is missing, of an image-capturing sensor having a plurality of pixels which are arranged in a two-dimensional array and output color information corresponding to different color components, which are firstxcx9cnth (nxe2x89xa72) color components, each of the plurality of pixels outputting color information corresponding to a single color component. The interpolation processing program comprises: a similarity degree calculation step in which each of similarity degrees along, at least, two directions relative to an interpolation target pixel to undergo interpolation processing is calculated based upon color information at a plurality of pixels selected from the interpolation target pixel and pixels near the interpolation target pixel, for each of two types of similarity degrees, which are a xe2x80x9cdifferent-color similarity degree containing a different-color similarity component obtained by using color information corresponding to different color componentsxe2x80x9d and a xe2x80x9csame-color similarity degree containing a same-color similarity component obtained by using color information corresponding to a single color componentxe2x80x9d, by switching to either type of similarity degrees or switching weighting ratios to be used in weighted addition of the similarity degrees in correspondence to characteristics of an image over a local area containing the interpolation target pixel; a similarity judgment step in which a judgment is made on degrees of similarity along the individual directions based upon the similarity degrees; and an interpolation quantity calculation step in which an interpolation quantity for the interpolation target pixel is calculated based upon results of the judgment made in the similarity judgment step.